On Fri, Jun 26, 2015 at 12:58 PM, Gioh Kim <gioh.kim@xxxxxxx> wrote:
> Apply driver page migration into balloon driver.
>
> Signed-off-by: Gioh Kim <gioh.kim@xxxxxxx>
> ---
> drivers/virtio/virtio_balloon.c | 3 +++
> fs/proc/page.c | 3 +++
> include/linux/balloon_compaction.h | 33 +++++++++++++++++++++------------
> include/uapi/linux/kernel-page-flags.h | 2 +-
> mm/balloon_compaction.c | 19 +++++++++++++++++--
> 5 files changed, 45 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 82e80e0..c49b553 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -505,6 +505,9 @@ static int virtballoon_probe(struct virtio_device *vdev)
> balloon_devinfo_init(&vb->vb_dev_info);
> #ifdef CONFIG_BALLOON_COMPACTION
> vb->vb_dev_info.migratepage = virtballoon_migratepage;
> + vb->vb_dev_info.inode = anon_inode_new();
> + vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops;
> + mapping_set_migratable(vb->vb_dev_info.inode->i_mapping);
> #endif
>
> err = init_vqs(vb);
> diff --git a/fs/proc/page.c b/fs/proc/page.c
> index 7eee2d8..2dc3673 100644
> --- a/fs/proc/page.c
> +++ b/fs/proc/page.c
> @@ -146,6 +146,9 @@ u64 stable_page_flags(struct page *page)
> if (PageBalloon(page))
> u |= 1 << KPF_BALLOON;
>
> + if (PageMigratable(page))
> + u |= 1 << KPF_MIGRATABLE;
> +
> u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
>
> u |= kpf_copy_bit(k, KPF_SLAB, PG_slab);
> diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
> index 9b0a15d..e8a3670 100644
> --- a/include/linux/balloon_compaction.h
> +++ b/include/linux/balloon_compaction.h
> @@ -48,6 +48,7 @@
> #include <linux/migrate.h>
> #include <linux/gfp.h>
> #include <linux/err.h>
> +#include <linux/fs.h>
>
> /*
> * Balloon device information descriptor.
> @@ -62,6 +63,7 @@ struct balloon_dev_info {
> struct list_head pages; /* Pages enqueued & handled to Host */
> int (*migratepage)(struct balloon_dev_info *, struct page *newpage,
> struct page *page, enum migrate_mode mode);
> + struct inode *inode;
> };
>
> extern struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info);
> @@ -73,24 +75,28 @@ static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
> spin_lock_init(&balloon->pages_lock);
> INIT_LIST_HEAD(&balloon->pages);
> balloon->migratepage = NULL;
> + balloon->inode = NULL;
> }
>
> #ifdef CONFIG_BALLOON_COMPACTION
> -extern bool balloon_page_isolate(struct page *page);
> +extern const struct address_space_operations balloon_aops;
> +extern bool balloon_page_isolate(struct page *page,
> + isolate_mode_t mode);
> extern void balloon_page_putback(struct page *page);
> -extern int balloon_page_migrate(struct page *newpage,
> +extern int balloon_page_migrate(struct address_space *mapping,
> + struct page *newpage,
> struct page *page, enum migrate_mode mode);
>
> /*
> - * __is_movable_balloon_page - helper to perform @page PageBalloon tests
> + * __is_movable_balloon_page - helper to perform @page PageMigratable tests
> */
> static inline bool __is_movable_balloon_page(struct page *page)
> {
> - return PageBalloon(page);
> + return PageMigratable(page);
> }
>
> /*
> - * balloon_page_movable - test PageBalloon to identify balloon pages
> + * balloon_page_movable - test PageMigratable to identify balloon pages
> * and PagePrivate to check that the page is not
> * isolated and can be moved by compaction/migration.
> *
> @@ -99,7 +105,7 @@ static inline bool __is_movable_balloon_page(struct page *page)
> */
> static inline bool balloon_page_movable(struct page *page)
> {
> - return PageBalloon(page) && PagePrivate(page);
> + return PageMigratable(page) && PagePrivate(page);
> }
>
> /*
> @@ -108,7 +114,7 @@ static inline bool balloon_page_movable(struct page *page)
> */
> static inline bool isolated_balloon_page(struct page *page)
> {
> - return PageBalloon(page);
> + return PageMigratable(page);
> }
>
> /*
> @@ -123,7 +129,8 @@ static inline bool isolated_balloon_page(struct page *page)
> static inline void balloon_page_insert(struct balloon_dev_info *balloon,
> struct page *page)
> {
> - __SetPageBalloon(page);
> + page->mapping = balloon->inode->i_mapping;
> + __SetPageMigratable(page);
> SetPagePrivate(page);
> set_page_private(page, (unsigned long)balloon);
> list_add(&page->lru, &balloon->pages);
> @@ -139,7 +146,8 @@ static inline void balloon_page_insert(struct balloon_dev_info *balloon,
> */
> static inline void balloon_page_delete(struct page *page)
> {
> - __ClearPageBalloon(page);
> + page->mapping = NULL;
> + __ClearPageMigratable(page);
Please leave balloon pages marked as balloon.
Just check them in migration code like:
if (PageBalloon(page) || PageMobile(page)) ...
> set_page_private(page, 0);
> if (PagePrivate(page)) {
> ClearPagePrivate(page);
> @@ -166,13 +174,13 @@ static inline gfp_t balloon_mapping_gfp_mask(void)
> static inline void balloon_page_insert(struct balloon_dev_info *balloon,
> struct page *page)
> {
> - __SetPageBalloon(page);
> + __SetPageMigratable(page);
> list_add(&page->lru, &balloon->pages);
> }
>
> static inline void balloon_page_delete(struct page *page)
> {
> - __ClearPageBalloon(page);
> + __ClearPageMigratable(page);
> list_del(&page->lru);
> }
>
> @@ -191,7 +199,8 @@ static inline bool isolated_balloon_page(struct page *page)
> return false;
> }
>
> -static inline bool balloon_page_isolate(struct page *page)
> +static inline bool balloon_page_isolate(struct page *page,
> + isolate_mode_t mode)
> {
> return false;
> }
> diff --git a/include/uapi/linux/kernel-page-flags.h b/include/uapi/linux/kernel-page-flags.h
> index a6c4962..65db3a6 100644
> --- a/include/uapi/linux/kernel-page-flags.h
> +++ b/include/uapi/linux/kernel-page-flags.h
> @@ -33,6 +33,6 @@
> #define KPF_THP 22
> #define KPF_BALLOON 23
> #define KPF_ZERO_PAGE 24
> -
> +#define KPF_MIGRATABLE 25
>
> #endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */
> diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
> index fcad832..df72846 100644
> --- a/mm/balloon_compaction.c
> +++ b/mm/balloon_compaction.c
> @@ -131,7 +131,7 @@ static inline void __putback_balloon_page(struct page *page)
> }
>
> /* __isolate_lru_page() counterpart for a ballooned page */
> -bool balloon_page_isolate(struct page *page)
> +bool balloon_page_isolate(struct page *page, isolate_mode_t mode)
> {
> /*
> * Avoid burning cycles with pages that are yet under __free_pages(),
> @@ -175,6 +175,9 @@ bool balloon_page_isolate(struct page *page)
> /* putback_lru_page() counterpart for a ballooned page */
> void balloon_page_putback(struct page *page)
> {
> + if (!isolated_balloon_page(page))
> + return;
> +
> /*
> * 'lock_page()' stabilizes the page and prevents races against
> * concurrent isolation threads attempting to re-isolate it.
> @@ -193,12 +196,16 @@ void balloon_page_putback(struct page *page)
> }
>
> /* move_to_new_page() counterpart for a ballooned page */
> -int balloon_page_migrate(struct page *newpage,
> +int balloon_page_migrate(struct address_space *mapping,
> + struct page *newpage,
> struct page *page, enum migrate_mode mode)
> {
> struct balloon_dev_info *balloon = balloon_page_device(page);
> int rc = -EAGAIN;
>
> + if (!isolated_balloon_page(page))
> + return rc;
> +
> /*
> * Block others from accessing the 'newpage' when we get around to
> * establishing additional references. We should be the only one
> @@ -218,4 +225,12 @@ int balloon_page_migrate(struct page *newpage,
> unlock_page(newpage);
> return rc;
> }
> +
> +/* define the balloon_mapping->a_ops callback to allow balloon page migration */
> +const struct address_space_operations balloon_aops = {
> + .migratepage = balloon_page_migrate,
> + .isolatepage = balloon_page_isolate,
> + .putbackpage = balloon_page_putback,
> +};
> +EXPORT_SYMBOL_GPL(balloon_aops);
> #endif /* CONFIG_BALLOON_COMPACTION */
> --
> 1.9.1
>
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